1. Field of the Invention
The present invention relates to a remote maintenance system including a communication terminal device, such as a digital Multi Function Peripheral (MFP) and a facsimile machine, and a center device remotely managing a failure or the like in the communication terminal device, and also relates to the communication terminal device and the center device.
2. Description of the Related Art
A conventional remote maintenance system remotely monitors an operation status of various electronic equipments and devices installed in home, offices, factory, etc. and carries out a maintenance on a target device when an abnormality generates. In such a remote maintenance system, specifically, a remote diagnosis is performed via a telephone line, and a remote service center controls a reading process of data stored in a terminal device and a writing process of data in the terminal device.
In the conventional remote maintenance system, when a user originates a call through a Public Switched Telephone Network (PSTN), the user is charged for communication costs. In addition, only low-speed data communication can be performed over the PSTN, and the PSTN is not suitable for data communication of a large quantity.